1. Field of the Invention
The present invention relates to a voice mail system, and more particularly, to a voice mailbox management method in a voice mail system having a mutual notification function between a user mobile telecommunications terminal and a voice mail server, using an extended short message service.
2. Description of the Related Art
The worldwide market for mobile telecommunication terminals, which provide convenient communication, is rapidly expanding. The technological era of mobile telecommunication terminals which began with analogue cellular phones has seen the introduction of digital cellular phones, and now, personal communications services (PCS) phones. In line with developing mobile telecommunications technologies, access from personal portable/mobile telecommunications terminals (hereinafter, referred to as “a user terminal”) to data networks such as the Internet has been enabled, and a variety of character services and data services, such as facsimile, as well as voice services are being offered. Though the term mobile telecommunications services covers all communications services through wireless media in a broad sense, mobile phone service via wireless media will be mainly focused on, here.
In data communication networks such as the Internet, voice mail means an e-mail whose contents are voice data. In general, contents of e-mails are primarily characters. In line with development of multimedia technologies, however, the contents of e-mails are extending to include voice, photos, and images. Meanwhile, voice mail in a mobile telecommunications network means a short message of voice and/or callback number to a corresponding user terminal through a service, usually referred to as a voice mailbox, offered by a voice mail server when establishment of a mobile phone connection to a user terminal fails. When someone telephones through a mobile phone to other user terminal and the user terminal is turned off or is out of a connection-available area, then the call is connected to a voice mailbox in a voice mail server, and a voice message and/or a callback number can be left to the corresponding user terminal in line with guidance of the voice mail server.
FIG. 1A is a schematic diagram of a conventional method for exchanging management information between a user terminal and a voice mail server, and the voice mailbox state of the user terminal and the voice mail server when a new voice message is received in a voice mailbox in the voice mail server.
As shown in FIG. 1A, when a new voice message is received in a mailbox of a voice mail server, the voice mailbox in the voice mail server is set to a “new message 01” state, which means one new voice message is in storage. When a new message is received, the voice mail server waits for the user terminal to return to a connection-available state, and sends a short message informing the user terminal of the arrival of a new voice mail in step 110. A service supporting this transmission of a short message between a user terminal and a voice mail server (through a short message service server) is referred to as a Short Message Service. This is similar to the paging function in pager system. At present, the short message service supports up to about 160 characters. A voice mail notification service which informs a user terminal of the arrival of a voice mail in a voice mail server is a leading short message service.
When a user terminal receives a short message, usually, the arrival of a new message is presented on the display of the user terminal together with an alarm sound, and information on the voice mailbox in the user terminal is set to the “new message 01” state indicating that a new message is present. When an alarm of the user terminal indicates the arrival of a new message, the user is informed of the arrival of the new message in the voice mailbox.
Then, when appropriate, the user telephones the voice mail server in steps 120 and 122, hears the voice message stored in the user's voice mailbox according to guidance of the voice mail server, stores or deletes the message he heard in step 130 and finishes the call connection in step 132.
If the user deleted the voice message the user heard, the voice mailbox state of the voice mail server becomes “new message 00” (more accurately, “new message 00, stored message 00” state), and if the user stored the voice message, the state becomes “new message 00, stored message 01,”. However, after the user deletes the voice message in the voice mailbox of the voice mail server and finishes the call connection, information in the voice mailbox of the user terminal maintains the state “new message 01” because a separate short message is not sent between the user terminal and the voice mail server, though the state of the voice mailbox in the voice mail server has changed into “new message 00 (stored message 00)”.
Next, the case in which a user changes the voice mailbox state in the user terminal through individual deletion or total deletion will now be examined.
FIG. 1B is a schematic diagram of a conventional method for exchanging management information between a user terminal and a voice mail server, and the voice mailbox state of the user terminal and the voice mail server when a user modifies information of the voice mailbox in the user terminal.
For convenience of explanation, it is assumed that both a voice mailbox of a voice mail server and a voice mailbox of a user terminal are in the “new message 01” state, and the user confirms a callback number included in the new message in the voice mailbox on the user terminal, and deletes the voice message stored in the voice mailbox of the user terminal in step 100. Then, after information indicating that the corresponding message is deleted is presented on the user terminal display, information of the voice mailbox of the user terminal changes to the “new message 00” state. However, though a change in the state of the voice mailbox of the user terminal occurs, the voice mailbox of the voice mail server maintains the “new message 01,” state because a separate short message has not been sent between the user terminal and the voice mail server.
In the conventional method, the notification of the arrival of a voice mail to a user terminal is made only when a new voice mail arrives at the voice mailbox of a voice mail server, and when a user changes the voice mailbox state of a voice mail server after connecting to the voice mail server, a separate short message is not sent to the user terminal. Therefore, regardless of the change in the voice mailbox of the voice mail server, the user terminal maintains the existing information until a next new message is sent. After all, when a user deletes the message in a voice mailbox of a voice mail server after connecting to the voice mail server, the voice mailbox of the user terminal continues to maintain the information indicating the corresponding message is in storage, which causes inconsistency between the voice mailbox states of the voice mail server and the user terminal.
In addition, when the user deletes information stored in the voice mailbox of the user terminal, the deletion is made only in the user terminal and the state of the voice mailbox of the voice mail server does not change. Therefore, when a user changes information in the voice mailbox of the user terminal, inconsistency between the voice mailbox states of the voice mail server and the user terminal occurs.
Also, because new messages and stored messages are not separately managed in the voice mailbox of a user terminal, an inconsistent aspect exists considering that new messages and stored messages are separately stored and managed in a voice mailbox of a voice mail server.
The inconsistency occurs because management information is not exchanged in real-time mode between the mailboxes of a user terminal and a voice mail server. Users feel substantial confusion due to the inconsistency between the voice mailbox states between user terminals and a voice mail server, but nothing has been stipulated for the problem in the current short message service for the voice mail system.